How to read this
A space jellyfish is a rocket's exhaust plume lit by the Sun while the sky around the observer is dark. This page works out the geometry for each launch: where the rocket is, where the Sun is, and whether the plume is in sunlight while Charleston is not.
- Likely: every flight path we try has at least a minute of sunlit rocket above 5° in a dark sky. Possible: only some paths do. No: none do.
- Prime: the Sun is at least 6° below the horizon, so the sky is properly dark.
- The sky chart shows where to look. Your fist at arm's length covers roughly 10° of sky.
This is a geometry model only. It knows nothing about cloud, and its flight paths come from five Falcon 9 flights in 2018. In a first check against 4 reported plume sightings from the Charleston area it rated all 4 as likely, which is too few to call it proven. A launch that slips changes everything: check the time again before you go outside.